Here are some benefits of using Google Analytics during an optimization campaign:
1. It is completely free of charge. Although it is a free tool, but it still offer just as much or even more functionalities when compared to other paying tools.
2. Able to find out how your visitors locate your website. Other than the core set of keywords that you are optimizing, you will also be able to find out what other keywords your visitors type in to find your website. During the initial optimization campaign, the number of keywords may be little. But as time goes by, you will start getting more keywords being listed on organic listings, due to your overall optimization effort.
3. Able to identify which pages and links your visitors click the most. You will be able to know which are the popular pages and links, and measure whether your optimization campaign is directing the traffic to the correct pages.
4. Visitor segmentation. With this, you will be able to know how many new visitors that your search engine optimization campaign brings to you. You can segment your analytic result by new/returning visitors, geography and referral sources.
5. Able to fine tune your website. With this analytic report, you will be able to fine tune your website, and do a new copywriting on any page that is not converting well. In the end, it will bring you more quality prospects, and thus gaining more customers in the near future.